<!-- borrowed from Nuxt! -->

<template>
    <div class="progress" :style="{
        'width': percent + '%',
        'height': height,
        'background-color': canSuccess ? color : failedColor,
        'opacity': show ? 1 : 0
    }"></div>
</template>

<script>
export default {
  data () {
    return {
      percent: 0,
      show: false,
      canSuccess: true,
      duration: 3000,
      height: '2px',
      color: '#ffca2b',
      failedColor: '#ff0000'
    }
  },
  methods: {
    start () {
      this.show = true
      this.canSuccess = true
      if (this._timer) {
        clearInterval(this._timer)
        this.percent = 0
      }
      this._cut = 10000 / Math.floor(this.duration)
      this._timer = setInterval(() => {
        this.increase(this._cut * Math.random())
        if (this.percent > 95) {
          this.finish()
        }
      }, 100)
      return this
    },
    set (num) {
      this.show = true
      this.canSuccess = true
      this.percent = Math.floor(num)
      return this
    },
    get () {
      return Math.floor(this.percent)
    },
    increase (num) {
      this.percent = this.percent + Math.floor(num)
      return this
    },
    decrease (num) {
      this.percent = this.percent - Math.floor(num)
      return this
    },
    finish () {
      this.percent = 100
      this.hide()
      return this
    },
    pause () {
      clearInterval(this._timer)
      return this
    },
    hide () {
      clearInterval(this._timer)
      this._timer = null
      setTimeout(() => {
        this.show = false
        this.$nextTick(() => {
          setTimeout(() => {
            this.percent = 0
          }, 200)
        })
      }, 500)
      return this
    },
    fail () {
      this.canSuccess = false
      return this
    }
  }
}
</script>

<style lang="stylus" scoped>
.progress
    position fixed
    top 0
    left 0
    right 0
    height 2px
    width 0
    transition width .2s, opacity .4s
    opacity 1
    background-color #efc14e
    z-index 999999
</style>
